「Hardly」は副詞です。副詞の前に「no」を置いてはいけません。

"hardly" is an adverb. You can NEVER put "no" in front of an adverb.

❌ no <adverb>
❌ no hardly
❌ no quickly
❌ no coldly
✅ no <名詞>
✅ no effort ⟵ 「effort」は名詞です
✅ no money
✅ no problem

Compare:
✅ with no difficulty
✅ with hardly any difficulty == with almost no difficulties